Barry_Duffman
Member
No worries. You keep something going for free that appeals to a small set of a small community. Thank you for everything you do for us and I look forward to hacking into a chest freezer this weekend!
BrewPi Remix – What’s Old is New Again
- Thread starter LBussy
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Help Support Homebrew Talk:
OK, I have it working now, such fun! Ive spent an or or two reading up on everything PID, but sadly I don't yet feel comfortable deciding which param to adjust here.
Looking at my graph I note the cooling and heating appear to be applied right up to where the beer temp hits the target temperature. So of course, the beer temp both overshoots and undershoots, and the beer temperature fluctuates by +1 and -2c.
Im thinking this is related to Ki because its controlling the response to the size of the error. But I dont see how changing that would stop the overshoot. Somehow the algorythm needs to shut off both heating and cooling earlier, anticipating the overshoots.
It did occur to me it may need more time to adjust. I couldnt find any info on that. But then I notice that the overshoots no longer appear to be chaning in magnitude.
Its at this point I recall reading one of the common causes for bad PID tuning - modifying params without fully understanding them all!
Id be grateful if anyone can assist and educate me as to what to try and change and why. I might be able to do it by myself then. Or somewhere I havent found that would educate me to the same end.
The fermenter has 20L of water, thermowell down the middle. Enclosure is a bar fridge probably about 50% more volume than the beer bucket. The heater is a reptile enclosure globe 75W. And the fridge probe sits in open space in the bottom 1/3 of the fridge. BrewPi Remix is using default params.
The first hour or so of the following graph can be ignored (well, it doesnt represent the steady state, I was opening and closing the door)
OP
OP
I had a look, and this is not the one I thought it was. This is more than likely just a transitory issue negotiating SSL. You should try it again.
OP
OP
Clear any adjustments and let it run a day or so with the same thermal mass and see what happens. Yes, PID stands for "tempted end user to make bad mistakes." In the original Russian of course.
Barry_Duffman
Member
So uninstall using option 1 automated installer or reformat the SD card, use the imager, then use automated installer?
OP
OP
The uninstaller will get you to where the installer will run again. Your choice really.
![Craft A Brew - Safale BE-256 Yeast - Fermentis - Belgian Ale Dry Yeast - For Belgian & Strong Ales - Ingredients for Home Brewing - Beer Making Supplies - [3 Pack]](https://m.media-amazon.com/images/I/51bcKEwQmWL._SL500_.jpg)
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We no longer have to sacrifice a virgin DIMM to the Bit Gods, while facing Silicon Valley, while reciting from Peter Norton’s Inside the IBM PC??!!
OP
OP
YOU do.
Barry_Duffman
Member
So now I'm getting a different error consistently for the last three install attempts. From what I could glean from Google searches piwheels numpy is received but not authenticated by the automated install. Maybe there is a new version of numpy but I'm just guessing and reading about it though educational for the last 30 minutes doesn't help me to actually install BrewPi. Thanks for any insights you guys can provide.
I decided to try a fourth time and completed the automated installation but now have an issue with the web portal not launching the script.
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In control constants the annotation says
The default value, which it currently is, is 0.5c.
My interpretation is: Pi is not active if my overshoot or undershoot is greater than 0.5c about the set point. Is this a correct interpretation?
If it is, it explains why my temperature fluctuations are still exactly the same as 6 hours ago, namely +25.4c +21.99. Although Im waiting for a longer period to see some change, Im seeing absoutely nothing at the moment.
OP
OP
Freaking numpy.
I am having some surgery this week (no, @Thorrak, not to remove my head from my ass) and I am not going to be able to get to this quickly. Sorry about that.
Best of luck, Lee! 
Barry_Duffman
Member
Speedy recovery LBussy. Thanks again for helping me work out all the kinks.
OP
OP
I think that's the
I value. Honestly, PID is one of those things that needs some time OR an excellent calculator/loop tuning if you want to dive in. It's rare that a standard-ish heat/cool setup on 1-10 gallons ever needs tweaking. When I thought I wanted to use my degree to be an Engineer, I went from dirt engineering to controls, which you had to do every day for a while before it started making sense.That particular PID loop is well-worn and probably has not been changed since Elco and company put it in the Uno. The programming is squeezed in so freaking tight (I had to shorten 16 characters worth of text fields to add the serial LCD screen reset) there was never an opportunity to go in there and do much, so I never peeled that particular onion.
When folks have severe overshoots (as in using Glycol or a very overpowered heat/cool setup), the general recommendation is to zero the values.
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Numpy can wait, get better first.
OP
OP
That section loops through a list using apt. You might try
sudo apt install x where x is one at a time of these:- libatlas-base-dev
- python3-numpy
- python3-scipy
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Barry_Duffman
Member
So I went through the commands and it appears to me that everything is properly installed. I went ahead and executed an option 1 uninstall of BrewPi then used the automated install tool. I can access the BrewPi.local web portal but I get "cannot connect to script" and "script not running" even giving it some time. When I go to configure devices and refresh nothing ever comes up.
OP
OP
The logs should give a clue now. Check /home/brewpi/logs/ and there’s an error and run log.
However, if you have not rebooted after all the machinations, that might work.
Barry_Duffman
Member
So I went ahead and rebooted earlier today and gave it a few hours and still the "script not running" issue. I tried using chrome, Microsoft Edge, and firefox with the same results. I opened the /home/brewpi/logs/ folder and all three files there were empty (ReadMe.md, stderr.txt, stdout.txt).
OP
OP
Barry_Duffman
Member
Sorry for the long paste but I wasn't sure what all would be pertinent from the daemon log. Looks as though the numpy thing is still an issue but I don't really know what to do beyond the install commands I already used from the piwheels website. Thanks again for all the support.
OP
OP
Do you have a tilt?
Barry_Duffman
Member
No and I selected N every time I've installed BrewPi using the auto instillation tool.
Barry_Duffman
Member
Any thoughts on what I should do concerning the "script not running" and numpy issues I'm experiencing?
thestraw0039
Active Member
Any chance you have Numpy installed by pip and the package manager?
Try this code, if it's installed with pip this will get rid of it. It may need sudo I don't know for sure.
Try this code, if it's installed with pip this will get rid of it. It may need sudo I don't know for sure.
Code:
pip3 uninstall numpy
OP
OP
Sorry, I was stuck in bed for a week.
There is/was a library issue because Python people did Python things. I pushed a change to
main this morning that should address it, but it will need a clean install. I am not sure it will work, but if you want to try something before that, you could try:
Code:
sudo apt-get install libopenblas-devThe problem is detailed in issue #212.
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Recover fast good sir.
fwiw, the link under the text "issue #212" is "http://sudo%20apt-get%20install%20libopenblas-dev/"
OP
OP
Anyone who knows what to do with the issue text should probably be able to figure that one out.
Barry_Duffman
Member
So I used the "sudo apt-get install libopenblas-dev" on my current install and fixed my issue and the web portal ran the script. However the error returned while trying to add devices through the web portal. No amount of reboots or tweaking could fix it so I uninstalled BrewPi then reinstalled. There was an issue detecting the model/version of the Arduino Uno so I chose to treat it like a new controller and flash it using the defaults from the prompts (revC). The script didn't run again after this but I went into the utilities and used doFlash.sh to flash the controller which still had the issue detecting the model/version of Arduino Uno but I picked the defaults (revC) and now it works.
TLDR it works and I'm now at a learning how the software and settings work point so I'm good until my SSRs arrive next week...
I included everything that happened in case its of use to you but I don't really know why flashing the Arduino Uno eventually worked or why it had issues detecting the model/version.
Thank you so much for being so responsive and a speedy recovery for sure.
TLDR it works and I'm now at a learning how the software and settings work point so I'm good until my SSRs arrive next week...
I included everything that happened in case its of use to you but I don't really know why flashing the Arduino Uno eventually worked or why it had issues detecting the model/version.
Thank you so much for being so responsive and a speedy recovery for sure.
